The principal that yields a simple interest of ₹ 1,280 at 16%per annum for 8 months is:

The simple interest on ₹ 5,000 at 2% per month for 3 months is:

The time in which simple interest on a certain sum be 0.15times the principal at 10% per annum is:

A time interval of 3 minutes and 20 seconds is wrongly measured at 3 minutes and 25 seconds. What is the percentage error?

Hari reads 22% of the pages of a book on the first day, 53% on the second day and 15% on the third day. If the number of pages remaining to be read is 30, find the total number of pages in the book.